Although opaque or solid matter blocks the transmission of light through the body or volume of opaque material, microscopes are still utilized to examine the surface of such solid materials. While opaque samples are often macroscopic, their size is such that they are often difficult to manipulate by hand. For example, prior to microscopic examination, the surface to be examined must be polished. The size of most samples prohibits the necessary polishing of a sample that is held by hand. For this reason, macroscopic samples are mounted or attached to a support of sufficient length to allow a person to hold a sample comfortably by hand and manipulate it to carry out the required polishing operations.
The samples are usually attached permanently to the sample supports effectively making the support integral with the sample placed under the microscope. Consequently, the sample surface to be examined is often more than one centimeter above the level of the microscope stage. This height frequently decreases the available distance that is required to move the microscope objective into focus. This problem becomes enhanced as the longer higher power objectives are positioned over the sample. Often, there is not enough clearance to bring the objective into position over the sample-sample support assembly.
U.S. Pat. No. 4,477,157 to Gaul attempts to solve this problem by providing a double revolving microscope stage. Vertical adjustment means are provided to allow the bottom stage to be raised or lowered vertically without rotating the stage. The '157 patent provides separate vertical and rotational controls using pinion and gear mechanisms that are controlled using knurled knobs.
Although the '157 patent enables examination of crystal-optical and other opaque samples, it does not provide a simple method for manipulating the sample. The double revolving stage assembly is bulky, awkward and requires precise machining of numerous small parts. In addition, the several control knobs are placed on top of the stage or at the side of the stage. The proximity of the controls to the sample increases the likelihood of a user unintentionally moving or damaging the sample when trying to move the stage.
What is needed, then, is a revolving stage that allows for the creation of sufficient distance between macroscopic samples or support mounted samples and microscope objectives, especially medium power and high power objectives, such as 40× and 100×, respectively. Moreover, what is further required is a method and apparatus to manipulate the sample and stage to satisfactorily perform microscopic examinations of opaque samples without undue interference with the sample itself.